1. Field of the Invention
The present invention pertains generally to devices for transporting portable articles and finds application in facilities such as hospitals, hotels, schools and the like, and pertains more particularly to a knock-down utility cart that is easy to manufacture, easy to ship in knocked-down condition from the point of manufacture to the point of use and that can readily be assembled and later disassembled for compact storage.
2. Description of the Prior Art
Utility carts of the class described are provided with four casters and may include four corner posts, a handle at one or both ends of the cart and two or more shelves supported by the corner posts. Such carts have been manufactured of all welded construction or in knock-down form.
One serious drawback of the all welded construction resides in the fact that the carts are expensive to warehouse and ship because of their size. Additionally, they may not be disassembled for compact storage when not in use.
With respect to the knock-down carts, it is known to provide U-shaped members at one or both ends, the legs of such members serving as a pair of corner posts and the bight serving as a handle. Each such U-shaped member may be provided with vertically spaced exterior annular grooves on the vertical legs to engage with tapered sleeves or post supports, as shown in U.S. Pat. Nos. 3,424,111 (Maslow), and 3,874,511 (Maslow), used to support shelves.
Several problems result from the use of these U-shaped members. First, because these members are made by rolling the grooves into a straight length of tubing and then bending the tube into its final shape, and because the accuracy of bending is dependent on several factors including the mechanical properties of the tubing, it sometimes occurs that the legs are not of precisely the same length or that the grooves in the respective legs do not precisely align horizontally. As a result, in one instance, all four casters do not engage the floor and consequently the cart wobbles, and in another instance, the four corners of a shelf do not engage uniformly with the associated tapered sleeves or post supports.
Second, since the bight of the U-shaped members precludes the placement of shelves over the top of the posts, carts employing the U-shaped members are normally assembled by the user from the bottom up, each shelf being positioned on the four straight corner posts in order from the top shelf down. This is a difficult procedure.
Finally, use of the U-shaped members necessitates that the casters be installed by the user at the bottom of the corner posts since, if they were installed at the factory, it would be impossible for the user to install the shelves. Installation of the casters has been found to be an especially troublesome procedure for those not familiar with appropriate techniques.
Constructions have been proposed in the past in which each U-shaped member was formed as three pieces, namely one U-shaped handle and two separate corner posts. In such constructions, a tubular coupling axially split at both ends was inserted with a resilient friction fit into respective mating ends of the handle and each corner post. This structure was not entirely satisfactory, however, because it was difficult to assemble due to the friction fits between the coupling and corner posts and handle. Moreover, the handle could be dislodged from the couplings and corner posts, despite the friction fits, if the handle was lifted for any reason.
Other teachings of interest in respect of the present disclosure are found in U.S. Pat. Nos. 3,523,508 (Maslow) and 3,927,769 (Maslow).